Transition Networks
SISGM
–CHAS L2/L3 Switch User Guide
33625 Rev. B
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46
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4.4.3
CIST
With the ability to cross regional boundaries, CIST is used by MSTP to communicate with other
MSTP regions and with any RSTP and STP single-instance spanning trees in the network.
Any boundary port, if it is connected to another region, will automatically belong solely to CIST,
even if it is assigned to an MSTI. All VLANs that are not members of particular MSTIs are
members of the CIST.
Port Settings
This page allows the user to inspect the current STP CIST port configurations, and possibly
change them as well. This page contains settings for physical and aggregated ports. The
aggregation settings are stack global.
The STP CIST Port Configuration parameters are described below.
Label
Description
Port
The switch port number to which the following settings will be applied.
STP Enabled
Check to enable STP for the port.
Path Cost
Configures the path cost incurred by the port.
Auto
will set the path cost according to the physical link speed by using
the 802.1D-recommended values.
Specific
allows you to enter a user-defined value. The path cost is used
when establishing an active topology for the network. Lower path cost
ports are chosen as forwarding ports in favor of higher path cost ports.
Valid values are 1 - 200000000.
Priority
Configures the priority for ports having identical port costs (see above).